1. Field
Example embodiments relate to setting parameters in semiconductor chips. Also, example embodiments relate to option circuits and option methods of semiconductor chips, in which information such as operation parameters may be changed even after semiconductor packages have been assembled.
2. Description of Related Art
Generally, a semiconductor chip includes a fuse option circuit so that internal parameters of the semiconductor chip may be controlled in a wafer test process. The fuse option circuit may be programmed by laser-cutting in the wafer test process.
After a semiconductor device including the programmed semiconductor chip is packaged in a package assembly process, the semiconductor package is tested. A soldering option, an electrical fuse (e-fuse) option, a mode register set (MRS) option, etc., are provided for the semiconductor chip so that the internal parameters may be changed in the package test process.
The soldering option is difficult to implement because of space limitations of the semiconductor chip that are encountered as a number of pins increases. However, the soldering option has an advantage in that a signal of the semiconductor chip may be artificially changed by external manipulation so that an operation mode may be easily changed. That is, even though each of a plurality of semiconductor chips is packaged to have the same operation mode as one another, each of the semiconductor chips may be set to have a different operation mode from one another by the soldering option.
The fuse option, the e-fuse option, the soldering option, etc., may be referred to as hardware options that are used in mechanically or physically changing the options, while the MRS option may be referred to as a software option with which external test equipment sends commands to the semiconductor chip so that a mode register value in the semiconductor chip may be changed.
FIG. 1 is a circuit diagram illustrating a related art option method of a semiconductor chip.
Referring to FIG. 1, a register value is changed by multiplexing a signal outputted from a hardware option, such as a soldering option, an e-fuse option, a fuse option, etc., and a signal outputted from a software option, such as a MRS option.
In the related art option method, only one of the hardware options may be inputted to a multiplexer MUX. Then, either the inputted hardware option or the software option, but not both, is selected by applying a control signal CON to the multiplexer MUX. As a result, more than one of the hardware options may not be used at the same time.
Thus, for example, when fuse information needs changing after packaging a semiconductor chip, the fuse information may be changed by cutting a corresponding fuse only after the semiconductor package is disassembled. That is, the fuse information may not be changed without disassembling and then reassembling the semiconductor package.
In a mass-production test process for memory chips, environments in which a user may arbitrarily change test parameters are needed. For example, when the memory chips need to be tested with respective clock signals having duty ratios different from each other, an option program is needed in order to change the duty ratio of the clock signal.
However, the option program, such as a duty ratio, is set by a fuse option before packaging the semiconductor chip. Thus, after packaging the semiconductor chip, it is difficult to change parameters of the semiconductor chip that provide the clock signal to the memory chip to be tested. Therefore, a user has restrictions in managing the test because it may not be possible to perform the test with a variety of parameters.